Tony Soprano sits at a table in the back of Irish Lion (a bar & restaurant) waiting for visitors. If the chair opposite Mr. Soprano is occupied, visitors wait at the bar. When the chair becomes free, the next visitor sits down and talks to Mr. Soprano. Visitors arrive randomly at a rate of ten per hour. Once seated, the visitor does not leave until Mr. Soprano has finished the conversation. Mr. Soprano is quite unpredictable. The lengths of his conversations are random, and have a mean time of four minutes. Once the conversation is over, the visitor always leaves the restaurant. Each visitor pays to the bar manager for the time waiting in the bar. The payment rate is $0.8 per minute. On average how much will each visitor pay to the bar manager?